2385: R and R

The theme is two historic people who were contemporaries. Unclued lights give their forenames, places of birth and death and occupations. A geographical feature (5) linking the two will appear in the completed grid and must be shaded. Elsewhere, ignore an apostrophe. The solutions at 22 and 27 share the same two unchecked letters.
 

Across

4    Harmless wag recast an economic principle (11, two words)
11    Eating away, in love indeed with empty oarsman (7)
14    Sarah acquires seemingly good old watch (5)
16    Papa gets behind in river race (5)
19    Many ships fighting lass boards (7)
21    Strange duke whipped lasher (4)
24    Insect sting upset (4)
25    I’m inspiring liberal peer to house Amerind (7)
32    Roué playing bubbly music (7)
34    Astronomer loves radio telephony (4)
36    Rare mineral, very devil to screw in (7)
38    Note cruel tyrant cycling (4)
39    Muslim jurist nearly left after typical bigot advanced (7)
41    Poet’s place in heaven being Bluegrass State (5)
44    Plump little boys planted small tree (5)
47    Bertie twice has female flyer round for drink (7, two words)
 

Down

1    Eat, gobbling almost every item of food (7)
2    Kris possibly has use no longer for pebbled fabric (6)
3    Pole receiving second heart (5)
5    Thong emir’s worn (4)
6    Old aristo from Spain men start to like (4)
7    Holiday dresses – see-through? (7)
8    Slander involves brilliant colonel (murderer?) (7)
10    Grain harvest, one garnered by an Omani? (7)
15    Stunner shed tears … (5)
17    … when old Alun largely changed, becoming vegetative (7)
18    Person in need of P45 was this (4)
20    Plants spaniel destroyed (7)
22    Pater’s worried (3)
26    Larvae in river woman crosses (5)
27    Copy of recording tenor cut (3)
28    Sweet Patsy (4)
29    Hairstyle in fashion? Of course (7)
30    Letter consisting of note about chemical element (7)
31    Granny’s wonderful cotton cloth (7)
35    About fifteen tangled ropes (6)
37    Horlicks cross theologian imbibed (6)
40    Tunnel in Qatar leads to all nine air terminals (5)
42    Alto and treble perhaps make good (4)
43    Couple caught out bank (4)
 
A first prize of £30 for the first correct solution opened on 3 December.